Today it seems necessary to reliably control attempts at introducing or removing some products, for example but not exclusively explosive substances, to or outside of a sensitive zone.
The pertinent problem covers a very wide range of situations which especially encompass and not limitedly attempts to introduce products to a protected zone, such as a shop, a school, a train station, a public or private institution, or the attempt to remove products to outside a defined perimeter, for example in the event of theft from a company or on a protected site.
It eventuates these days that individuals who try to fraudulently remove a product from a protected zone or who try to introduce such a product, often use shoes to conceal the product in question.
This phenomenon seems due essentially to the fact that this zone is not easy to control visually or by manual handling.